The defense official said no decision had been made, and that if any additional forces are sent to Syria they will likely be redeployed from elsewhere in the region. The troops would patrol the proposed buffer zone.
The US and Turkey have been working to establish the buffer zone, which the US calls a "security mechanism," in northeast Syria as part of a bid to prevent a military incursion into the area that would target Syrian Kurdish groups, a potential operation that the US fears could undermine the fight against ISIS.
The New York Times was first to report the possible additional deployment, saying it would involve some 150 troops.
The US military's involvement along the Syria-Turkish border includes manning observation posts as well as patrolling with Turkish troops in the area.
"While we are working to implement the President's direction to withdraw troops from Syria in a deliberate and coordinated manner, force levels will be dictated by conditions on the ground," said Cmdr. Sean Robertson, a Pentagon spokesman. "For security reasons, we are not going to discuss numbers or timelines."
Since the US began drawing down its troops from a peak of just under 3,000 earlier this year, American forces there have been stretched thin by the need to monitor the border area while also advising the Kurdish-led Syrian Democratic Forces as they hunt down the remnants of ISIS.
In December, President Donald Trump announced that he would withdraw all US troops from Syria, an announcement that sparked the resignation of then-Defense Secretary Jim Mattis.
Trump later partially reversed his decision, agreeing to a small residual US presence to help ensure stability and hunt the remnants of ISIS.
While the Pentagon does not talk troop numbers in Syria, officials tell CNN that the military has reduced the number of US troops there to about 1,000.
Based on CNN